1. Field of the Invention
The present invention relates to silk textiles, and more particularly, to a simple, all-natural process that improves the physical properties of silk and silk textiles.
2. Description of Related Art
Silk is a fiber obtained as a filament from a cocoon produced by a silkworm. The silkworm can be a larva of the Chinese silkworm moth, Bombyx mori, or a larva of several moths of the Satumiidae family. A textile is any cloth or goods produced by weaving, knitting, or felting. Materials such as natural and synthetic fibers or yarn that are suitable for weaving are also textiles.
Silk textiles are very popular and widely used for clothing purposes because of their elegant appearance and comfort. Silk textiles generally dye well, they can be woven or knit, and they have the ability to retain heat in cold weather while staying cool in hot weather. However, natural silk textiles generally wrinkle, do not stretch, and deform permanently if machine washed. Although silk can be dry cleaned, dry cleaning is expensive and is relatively ineffective at removing certain types of stains such as perspiration stains.
Chemical finishes exist that improve certain commercially important properties of silk. For example, glyoxal resin finishes with ethylene urea are reported to produce a silk textile having good crease-recovery, particularly when used with a metal-acid catalyst. Urethane resins with or without formaldehyde are reported to be suitable for producing machine-washable silk. Further, it is known that epoxides, siloxanes, amino-plasts and glyoxal can be dispersed in a sodium-hydroxide solution and applied to silk textiles to increase the washability of the textiles. Similarly, application of hydroxymethylmetracrylamine may improve crease-resistance and dimensional stability. A combination of glycerol and ammonium chloride may also increase wrinkle recovery.
There also exist materials consisting of silk blended with synthetics, such as Lycra.RTM., to make a stretchable fabric. A formaldehyde-free silk finishing process that uses a monobasic acid, a polycarboxylic acid and a phosphorous-containing salt catalyst that can improve crease-resistance of silk textiles without decreasing their durability is disclosed in U.S. Pat. No. 5,296,269 to Yang.
However, problems associated with these prior art processes that use artificial chemicals arise because they may cause associated health problems or are potential allergens. In addition, not all of the limitations of natural silk are resolved. The wide appeal of silk textiles for use in clothing is based on several commercially important properties, but improving one or two of the properties, at the expense of others, does not fulfill a need for silk textiles that are elegant, comfortable to wear, machine-washable, stain proof, wrinkle proof, and stretchable.
Accordingly, the need exists for a natural silk textile that overcomes the drawbacks of the prior art and has improved physical properties including stretchability, waterproof, wrinkle-resistant, stain-resistant, and overall improved wearability obtained by a simple, all-natural process that does not require the use of synthetics or artificial chemicals.